For appraising articles:
Painless evidence-based medicine R723.7 .P35 2008eb
This book looks at nothing but how to appraise articles of varying sorts. Clear definitions of different elements that must be examined in each kind of study.
Evidence-Based Medicine is the integration of best research evidence with clinical expertise and patient values. (Sackett DL, Straus SE, Richardson WS, et al. Evidence-based medicine: how to practice and teach EBM. 2nd ed. Edinburgh: Churchill Livingstone, 2000.)